The magic is ending soon for the long-running Harry Potter series, which will close out with the final part of “Harry Potter and the Deathly Hallows,” being released in July 2011. But filming is already over for its three stars — Daniel Radcliffe, who plays the boy wizard, and Emma Watson and Rupert Grint, who play his best friends Hermione Granger and Ron Weasley.

Now it’s time for them to look ahead to their future, and answer a question even a Hogwarts professor might have trouble seeing in a crystal ball: Can they make the transition from child actors to successful grown-ups?

Though he'll never escape being associated with Harry, Radcliffe has made some big strides in establishing an identity of his own. The latest: appearing alongside John Larroquette in the Broadway musical “How to Succeed in Business Without Really Trying.” Radcliffe stars as J. Pierrepont Finch in the latest revival of the venerable satire of the business world, playing a window washer who schemes and charms his way up the corporate ladder.

But the transition to adult success is not an easy one for any young celebrity, says Stephanie Zacharek, chief film critic for Movieline. “Because they’re working in this very weird world, a lot of things can go wrong for them. It isn’t what we would call a normal way to grow up. Different child actors handle it with varying degrees of success.”

For the Potter trio, all cast in their roles around age 10, the high-profile and long-term nature of the Potter series gives them several advantages over their peers. Perhaps the most important was relative stability as they were growing up.

“Warner Brothers [knew] that they were going to be stuck with these three people for a long time,” says Saint Paul Pioneer Press film critic Chris Hewitt. “One of the things they were specifically looking for [in casting the roles] were people from supportive families. The whole Lindsay Lohan thing has basically happened during the life of the Potter movies, and what a nightmare for them if one of those three had trod that path.”

So far, the Potter trio has avoided the kind of self-destructive, tabloid-baiting behavior that has dogged other child stars.

“The danger of that has probably passed. I think they’re through the birthing stage of becoming celebrities,” says Melissa Anetti, writer for Potter fan site The Leaky Cauldron and author of “Harry, A History,” a book about Potter fandom. “I think it would have been a much different thing if these had been filmed in California. Because then they’d have had celebrities around them at all parts of their lives, they would have been invited to parties left and right, [and] would have started making friends that indulged their less responsible desires. You would have seen a different story.”

“They’ve worked with a couple different directors, and some of the greatest actors in England, let’s not forget,” says Hewitt. “I think it’s hard to imagine how monumental it has turned out to be for all three of them. I wonder if there have ever been auditions in the entire history of moviemaking that were that huge. That took somebody that nobody had ever heard of and turned them into one of the biggest stars in the world with eight huge hits on their resume. That’s kind of crazy — they got one job and it’s set all of them for life, and given them the opportunity to have an interesting career if they can figure out how to make it work.”

Hermione and Emma Watson are similar
That may or may not involve acting, although all three are slated to appear in at least one upcoming film. Watson in particular is branching out beyond her role as high-achieving witch Hermione, having made inroads into the fashion world as a model and designing an eco-friendly clothing line with Alberta Ferretti. She’s also appearing in Kenneth Branagh’s upcoming drama “My Week With Marilyn.”

“From the get-go, she was the one who was like her character,” says Movieline’s Zacharek. “She’s proficient, she knows what she’s doing, and at the same time she’s incredibly likable. Her, I’ve never been worried about.”

Watson is also juggling acting and fashion with college at Brown University, a move Zacharek approves of: “Maybe it is better, especially if you have an unusual childhood, to do something that’s more normal for a change. Just go out there and be around regular people for a while. I don’t think it hurts an actor.” Watson recently dropped out of Brown temporarily to finish the last rounds of Potter promotion, but plans to return.

“It seems as though Emma’s going to have the most varied career out of everybody,” says Anetti. “I can see her being a lot more than just a pretty face as she gets older.”

Hewitt cautions that, given their limited appearances outside the Potter films, the jury is still out whether any of the three have the dramatic range to play more than the one role that made them famous.

“I still don’t know that we can tell yet how great any of them are going to be,” he says. “[The Harry Potter] movies are so much not really acting showcases anyway. I don’t think any of them have been given a huge amount of chances to show what they can do.”

Another hurdle is potential typecasting.

“At this point they are so closely tied to their onscreen personas as the trio that it will be hard to break free from that,” says Andrew Sims, writer for Potter fan site mugglenet.com and host of Potter-themed podcast Mugglecast. “Dan (Radcliffe) has done a good job of trying to break free of that image.”

Radcliffe branches out
As the Potter series’ central actor, Radcliffe has the highest public profile of the trio and is probably in the best jumping-off position for a post-Potter acting career. Forthcoming projects include gothic ghost story “The Woman In Black,” a remake of WWI war drama “All Quiet on the Western Front,” and an indie comedy, "The Amateur Photographer."

“He can take on these roles that are a little bit more prestigious,” says Zacharek. “From where we’re standing now, maybe there’s more open for him than someone like Rupert Grint.”

Radcliffe has been careful to take roles that show his willingness to break out of the boy-wizard mold, poking fun at himself in an episode of Ricky Gervais’ sitcom “Extras,” and jumping into the traditional actors’ proving-ground of Broadway in the dark psychological drama “Equus,” in which he appeared nude, before moving on to his current stage role.

“I think it’s smart for Daniel Radcliffe to have done a lot of stage work,” says Hewitt. “That gave him the opportunity to learn a lot, and from a lot of people who know what they’re doing. ... I think with all of them, the main thing that would be smart for them to do is something that they’re passionate about. And I think all of them are doing that.”

As for Rupert Grint, the redheaded young actor may find himself more hemmed in than the others by his alter ego, the affable but inept Ron Weasley.

“He’s got that ginger hair, which is a liability for people. I can say that because I’m a redhead myself,” laughs Zacharek. “He’s good-looking, but I don’t know if he’s leading man material.”

So far, Grint's non-Potter filmography has been limited to smaller, quirky English-made indie comedies including “Driving Lessons” and “Wild Target,” and starring as hapless British Olympic ski jumper Eddie Edwards in the forthcoming “Eddie the Eagle.”

“I think he’s also going to be hard to cast,” agrees Hewitt. “He’s sort of unusual looking... I don’t know that he’s going to be playing a lot of romantic leads, so he might be better as a character actor anyway.”

That’s certainly not a bad path for a future actor; after all, it’s working for another red-haired comic Brit, Simon Pegg. “It’s so hard to say because comedy is so hard to do,” says Zacharek. “I think it’s one of those things, he’ll have to just feel his way along, and see how it goes.”

Video: Will ‘Harry Potter’ ‘Succeed in Business’?

Closed captioning of: Will ‘Harry Potter’ ‘Succeed in Business’?

>>>back at 8:20. he's best known as
harry potter
but did you know
daniel radcliffe
is also a wizard on his feet? he's now singing and dancing in the stage production of "how to succeed in business without really trying." great to have you here. you debuted in "equus" where you were nude on stage. there was controversy about that.

>>yes.

>>which is harder, being nude in front of an audience or singing and dancing?

>>i don't know. probably -- well --

>>they're different.

>>very different reasons. singing and dancing, dancing isn't something that came naturally to me. i did a lot of lessons to do that.

>>being nude on stage comes naturally?

>>well, anyone can do it. if i have to choose one to do eight times a week it would be singing and dancing. over a long period of time that's more preferable.

>>you are a terrific dancer in this, but it took a lot of effort. you were not a natural.

>>not at all. when i wasn't filming a potter i was doing nine hours of training a week and on my days off from potter i would do three hours. i didn't want rob, our director, a fantastic choreographer, to have to censor himself in terms of toning down what he would want me to do. i wanted him to have as wide an array of tools at his disposal as he could which he now kind of does. i did -- as opposed to a couple years ago i couldn't have almost done my left from my right in terms of dancing. now i'm a lot better.

>>yeah. in the play, you play j. pierpont finch. he's a go getter. starts as a window washer and ends up as chairman of the board. when you were a kid, you were discovered in a theater.

>>yeah. that'smantromanticized version of the story. that's when i met the producers of potter for the first time. i don't think i'm nearly as cut throat as j. pierpont finch is but it was fun to play somebody unashamedly ambitious and completely obsessed by the idea of rising to the top.

>>are you ambitious?

>>for myself, definitely. i don't think i would ever let ambition get in the way of my morality which is the thing that separates me from finch. finch is somebody who -- yeah, is quite willing to do things that aren't necessariliy mother-in-lmorally upstanding to get ahead. but it's a testament to how well the character is written is you still like him despite the fact that not everything he does is kosher.

>>this is the
50th anniversary
of the musical. you're following in big shoes.
robert morse
,
matthew brodrick
. you're 21 and they were older in their 30s. fill in the blank. if they had age and experience, i have --

>>the confidence of youth. i don't know. it's one of the things that i think makes it a different production and what i bring to it is the fact that because he is -- well, because i am so young playing him so young it kind of makes you forgive a lot of the reprehensible behavior. oh, he's young, he doesn't know any better. whereas the temptation with an older person may be that he's manipulative. when somebody's 21 you forgive more.

>>the last film of the
harry potter
franchise comes out this summer. i know you said you have moved on, did your mourning, but what do you miss the most?

>>working with, you know, the crew on those films every day. i was close with the crew. being able to see some of my
best friends
every day was very, very special. i will miss that a huge amount.

>>we're glad that you are sticking around. that's for sure. great reviews you are getting.

>>they're not out yet, but people are enjoying it.

>>standing ovations, i understand. even though you don't read the reviews.